#define _CRT_SECURE_NO_WARNINGS 1
for (i = 0; i < 4; i++)
{

	for (j = 0; j < 4; j++)
	{
		sum = 0;
		for (k = 0; k < 3; k++)
		{
			sum += a[i][k] * b[k][j];
		}
		c[count1][count2++] = sum;
		if (count2 % 4 == 0)
		{
			count2 = 0;
			count1++;
		}
	}
}